Cured films produced by curing compositions containing polyimide or polybenzoxazole have been used widely for dielectric films, protective films, planarization films, and the like of semiconductor elements or display devices. Particularly in display devices, it is required to reduce the transmittance of a cured film in order to increase contrast in applications such as, for example, a dielectric layer of an organic EL display and a black matrix of a liquid crystal display. In order to prevent malfunction caused by penetration of light into a TFT for driving of a display device, a leak electric current, and the like, it is required to reduce the transmittance of a dielectric layer of an organic EL device or a planarization film to be provided on a TFT substrate of an organic EL display. Examples of a technology of reducing the transmittance of a visible region greater than a wavelength of 400 nm in a cured film include a method of adding a colorant, such as carbon black, an organic or inorganic pigment, and a dyestuff, to a resin composition like that seen in a black matrix material for liquid crystal displays, an RGB paste material, and the like. Since resin compositions containing such colorants have absorption in a exposure wavelength region of 400 to 450 nm, it is difficult to use them as positive type photosensitive resin compositions which are sensitized by making light reach to a film bottom and therefore the use as a negative type photosensitive resin composition such that a film thereof is photocured from its surface is common.
Examples of a technology of reducing the transmittance of a cured film of a positive type photosensitive resin composition include a positive type radiative resin composition comprising an alkali-soluble resin, a quinone diazide compound, and a coloring composition of a leuco dye, a developing agent, and so on (see, for example, patent document 1), a photosensitive resin in which a heat-sensitive material that will become black upon heating has been added beforehand (see, for example, patent document 2), and a positive type photosensitive resin composition comprising an alkali-soluble resin, a quinone diazide compound, a thermally coloring compound that colors upon heating and exhibits an absorbance maximum at 350 nm or more and 700 nm or less, and a compound that has no absorbance maximum at 350 nm or more and less than 500 nm and has an absorbance maximum at 500 nm or more and 750 nm or less (see, for example, patent document 3). These are technologies of reducing the transmittance of a cured film while keeping the transmittance in the exposure wavelength region of the resin film before curing high by using a coloring compound that colors due to energy, such as heat.
Therefore, these can impart both positive photosensitivity and negative photosensitivity to resin compositions with high versatility.